The purpose of this invention is to improve environmentally friendly cleaning or dewatering agents, and more particularly to provide a more effective and efficient process for cleaning or for dewatering a surface, by using as a rinsing agent, an azeotrope containing a volatile methyl siloxane (VMS); instead of rinsing with only a VMS.
Because of local, state, federal, and international regulations, aimed at restricting the use of certain chemicals, the search for suitable replacements is an ever increasing dilemma faced by the chemical and industrial sectors.
The replacement of "outlawed" chemicals with certain volatile methyl siloxanes (VMS) as a solvent substitute is now a viable approach however. Thus, in America, the Environmental Protection Agency (EPA) has now determined that volatile methyl siloxanes such as dodecamethylcyclohexasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, and decamethyltetrasiloxane, are acceptable substitutes for CFC-113 the chlorofluorocarbon (C.sub.2 Cl.sub.1 F.sub.3), and methylchloroform (MCF), for cleaning in closed systems, in metal cleaning, electronics cleaning, and precision cleaning applications, under their Significant New Alternatives Policy (SNAP).
Most recently, the EPA in Volume 59, No. 165, of the Federal Register, Pages 44240-44256, (Aug. 26, 1994), made public their determination that two more volatile methyl siloxanes "Octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane are acceptable alternatives to MCF and CFC-113" for cleaning in closed systems, in the same end uses under their SNAP policy.
By virtue of these acceptable EPA findings on certain volatile methyl siloxanes as solvent alternatives, the demand for VMS materials is now increasing. With increased use and demand goes a corresponding demand for more effective and efficient processing techniques.
While the current use of VMS in washing applications is effective, it has unexpectedly been discovered that their use in two-step methods can be improved according to the techniques of this invention. Thus, the problem to be solved by this invention is to improve two-step washing which use VMS. This problem is solved by employing VMS in the rinsing step in the form of an azeotrope, instead of using only VMS for rinsing.